Bifuel internal combustion engine



mean 1, 1935. R. P. M. BOUDET 2,023,634

BIFUEL INTERNAL'COMBUSTION ENGINE Filed Dec. 26, 1933 2 Sheets-Sheet l Patented Dec. 10, 1935 BIFUEL IN'I'ERNAL COMBUSTION ENGINE Raoul Pierre Marius Boudeh-C ahuzacsur Vere,

France Application December 26,1933, Serial No. 103,910 1 In France December 31, 1932 a Claims. (01. 123-443 \This invention relates to the use of light fuels (petrol or the like) and heavy fuels (gas oil, heavy oil or the like) in internal combustion engines.

It has particularly for an object to ensure the regular ignition of the fuels, the instantaneous transfer from one fuel to the other or to a mixture of'the two, and the satisfactory operation of the engines. I

Heavy oil and the less volatile liquid combustibles, the utilization of which offers incontestable economic advantages, notably present the inconvenience of being difflcult-to ignite even when in the form of gaseous mixture with air. The spark of an ignition plug is insufficient to efiect their regular ignition and complete combustion. a

To obtain satisfactory operation and regular ignition of such mixtures, the present invention provides a process for feeding an internal combustion engine with light fuel (such as petrol) and heavy'fuel (suchas gas oil); characterized in that the ignition of the gaseous fuel-air-mixture admitted to the cylinder(s) is obtained by the ignition and explosion of a small quantity of a combustible volatile mixture, and in that the engine induction is in communication with a source of supply of the heavy fuel-air-mixture base and with a source of supply of the light fuel-air-mixture, the communication being such that-by the interposition of control means the engine induces either the light fuel-air-mixture alone or the heavy fuel-air-mixture alone or the two mixtures simultaneously in any and instantaneously variable proportions.

Means for carrying out the invention may comprise one or more of the following arrangements:--

(a) Adapting to each cylinder an ignition amplifier comprising a small explosion cham--' ber open to an admission valve and a sparking plug. The supplying of the amplifier with a rich mixture of air and petrol or the like is effected by the existing carburettor or .by a special small carburettor. The body of the amplifier can be disposed on a spigot mounted in place of the sparking plug, the'spigot being provided to conduct and direct the flame of the explosion in the amplifier towards the middle of the compressionchamber and to oppose the entry of-the gaseous fuel mixture from the compression chamher into the amplifier chamber.-

(b) Utilizing, in combination with an amplifier as aforesaid, two carburettors; one a petrol cara or by a system of levers and thrust members,,or

burettor, for the light fuel, which can-feed the' amplifier and the engine cylinders, -the other for heavy fuel, feeding the cylinders only.- The two carburettors are connected to the inlet manifold by a three-way conduit, provided in its outlet 6- branch to the said manifold with a throttle regulating the induction and operated by the accel-' erator pedal or equivalent of the vehicle with which the engine is associated. The respective throttles of the two carburettors are coupled so 10 that the one is closed when the other is open, and actuated simultaneously by a rod or other means in such manner as to enable induction instantaneously through the one or the other carburettor or through both in any and instantaneously 15 variable proportions. With the engine operating on petrol, it sufllces for the driver to operate a rod or'a cable by hand to transfer from the light to the heavy fuel or vice versa, or to any desired combination.- The outlet throttle of the three- 20 way conduit to the inlet manifold can optionally. be controlled by rod or other means, and the throttles of the two carburettors can be controlled simultaneously by the accelerator pedal or other 25 means. I a

(c) Heating theheavy oil in a closed chamber in the absence of air, in a heater interposed in the conduit connecting the tank to the carburettor and receiving heat from theexhaustgas of the engine or from an electrical source, which also heats the carburettor and its air intake.

(d) Feeding a light mixture to the small chambers of the ignition amplifiers by a small special carburettor or by a. branch from the petrol carburettor providedwith a throttle or obturator 35 coupled with the outlet throttle of the three-way conduit and actuated simultaneously therewith by the accelerator pedal or other means, or coupled with the throttls of the two carburettors and actuated simultaneouslywith them.

(e) Actuating the admission valves of the small chambers of the amplifier from the engine valve gear, or by a train of gears and cam shafts,

by an electromagnetic,- hydraulic, pneumatic or other arrangement. I

(I) Disposing in the means for actuating'each of the admission valves of theamplifier chambers an adjustable element in such manner as to permit regulation of the timing and opening of these valves.

(g) Attaching the ignition amplifiers in pairs to the engine by means of a single bolt for each pair, anchored in a stirrup fixed to the holdingdown bolts of the head or-of the engine, and

the degree of 45 air and heavy fuel alone. when; after a stoppage or for any other cause, the air-heavy-fuel mixture is not sufdcientlyhot,

2 I ,a,oss,os4

'- pressingla cross-piece on the two ignition amplifiers, this cross-piece optionally supporting the means'actuating thesmall admission valves, in

. such manner that; the .unscrewing of this one. a boltienables removal of the two ignition amplifiers for inspection or repair, or for'replacement of the sparking plug for running on petrol as prior tothe application of the ignition apparatus.

The fulfilment of all these conditions ensures g l good operation with "provlsion for easy super vision and dismantling.

The. explosion flames are preferably, conducted with all ltheiripressure and. all "their heat t0.' the desired point'in the compression chamber of the andiheavy oil into the amplifier explosion cham- 2 o mixture and results;inmis-firing.

i The heavy fuel is conveniently reheated in a Jclosed chamber, sheltered from air, prior to entering the carburettor. When itis heated in,

- the. presence of an excess of air, it decomposes 25 and produces carbonizing, mis-flring, etc. From the fact that the ignition of' the heavy fuel-airmixtureis obtained by the flame of the explosion in the amplifier, it isnot necessary to heat it very strongly initially. When I the heavy fuel is 30 strongly heated, and the -ignition;-is not very 40 4 0n starting; operation is first effected with the mixture ofair andpetrol alone until the motor and the'heavy oil-are heated. After some min- .utes, the engine is operated on a mixture of airpetrol' and air-heavy-fuelgthen" on a'mixture of 1 return is instantaneously made to the air petrol mixture, thentransferredprogressively to the .1 air-heavy-fuel In known arrangements where there is onlyone carburettor for petrol andheavy oil it is necessary to use a certain quanti of \one fuel before transferring to the other, with the, result that picking-up is bad and carbonization may be "caused. e

A carburettor which is adjusted for petrol is incorrect for heavy on and conversely, and a petrol carburettor mustbe rather cold while one for 60 heavy oilmust be heated.

. The amplifier is fed with a rich mixture andadapted so that the-ignition plugs are cooled, in order to obtain the most regular operation and the minimum of nus-firing. Y 65 n The arrangements described permit regular operation on petrol and heavy fuel, for example gas 011,01 an ordinary engine constructed for operating on petrol, and it is unnecessary to continue operation on petrol except on'starting and to 70 facilitate picking-up when the engine and the ,1 heavy oil are cold. stalling at ;a critical mo-,

ment is no longer to be feared when it is possible toreturn instantaneously and exclusively to the air-petrol mixture by simply operating a rod or 75 other meanswithin reach of the driver's hand.

according to the invention,

With the amplifier, the volumetric consumption of fuel in operation with air-petrol and airgas-oil is substantially the same as that of operation-on air-petrol of an ordinaryengine.

Other characteristics of the'invention will be evident from the following description, solely by way of example, of its application to an existing four-cylinder petrol engine.

Referring to the accompanyingdrawings, Fig. '1, is a view in elevation of an.- apparatus Fig. 2 is a sectional view of the amplifier,

Fig. 3 isa view of the actuating means for the admission valves of the amplifier fromthe engine valve gear by means of an arrangement of the cams'and levers disposed between the engine and the ignition interruptor and actuated by the g interruptor shaft. 'bersisopposed, since it impoverishes the rich Figs. 4 and-6 are views of arrangements for atta'ching pairs of amplifiers, located by spigots, by means of. a single bolt anchored in a stirrup fixed to the cylinder head, and

Fig 5 is a view of the actuating means for the admission valves of the amplifiers by the valve gear directly by means of the tappets of the admission valves of the engine.

The elevation (Fig. 1). shows the feeding of gas oil by the tank I, previously utilized for petrol and now utilized for gas -oil', the outlet tap 2 with a filter, a conduit 3 from the reservoir to a heater 4, a conduit 5 from the heater to a gas-oil carburettor 6, an air heater I for the saidcarburettor and a regulable air inlet 8, the petrol feed byasmall tank 9, outlet tap l0 and conduit II from the tank to the petrol carburettor I2, having an adjustable air inlet l3.

connected'to thethrottle II of the gas-oil carburettor 6 by a rod l6 which joins the two throttle levers l1 and 18in such a manner that one throttleis closed when the other is open. The two throttles. and li are actuated simultaneously to by.a rod 25 passing through a guide 26 and provided with a ring 21 located within reach of the driver. The two carburettors 6 and i 2 are connected to the inlet manifoldof the cylinders by ,a three-way conduit 22, the throttle 23 of which is actuated by, the accelerator pedal.

The guide 26;.carries a spring and a detent which. maintain the rod 25 in its limiting positions upwards for operation on petrol anddown- .wards for operation on gas oil, and. in intermediate positions for operation on mixtures of the gases of the two fuels.

The ignition amplifier comprises four bodies 28, which are fed with air-petrol mixture by the manifold" and a conduit, which is branched from the petrol carburettor l2; the admission valves ll (Fig. 2) of the chambers in thebodies 28 of the amplifier are controlled by levers 32 actuated through tappets" by a face-cam 34 on a disc as carriedby'a shaft16.(Fig. a) which is driven by a shaft 31 actuating the ignition interthe head I maintain bolts, l2, of which each secures two of the amplifier bodies 28 by means aoaaoss of a cross-piece $3, the latter also supporting the axes of oscillation of the levers 32.

Fig. 2 shows in section an amplifier body 28 with an admission valve 3!, sparking plug N and spigot 45 screwed in place of the plug. P netrating deeply into the compression chamber of the engine, with a conical bore which directs and concentrates the jet of flame of the explosion on the desired point and opposes the entry of gases into the small explosion chamber by its interior section and its similarly conical exterior section.

Fig. 3 shows the arrangement for actuating the admission valves 30 of the amplifier bodies 28 by the levers 32, the tappets 33, the cam 34;, the disc 35, the shaft 36 actuated by the shaft 31 of the drive to the interruptor 38; the tappets 33 are guided in a socket 46 which bears upon the motor head M and supports the interruptor 3B, which is thus raised. It is only necessary to remove the socket 46 to replace the interruptor 38 in its original position.

Fig. 4 shows the securing in pairs of the amplifier bodies 28 by means of the cross piece 43 on the bolt t2; and the stirrup lii. Removal of the nut ll enables removal of the amplifier bodies 28 and replacement of the plugs M in their original positions ifdesired.

The application of the process and apparatus according to the invention to a motor'arranged like the Chevrolet is shown in Figs. 5 and 6.

Fig. 5 discloses an arrangement for direct operation of the small ignition valves 35 of the amplifier bodies 28 by tappets t8 actuated by the valve gear of the engine, adjustment being provided by screws 39.

Fig. 6 shows a mode of attachment in pairs of the amplifier bodies 28 illustrated in Fig. 5, by means of cross-piece 63 onbolt t2, and a stirrup to. Removal of the nut 4! enables removal of the bodies 28.

What I claim is:

1. System for feeding an internal combustion engine with light fuel, such as petrol, and heavy fuel, such as gas oil, comprising means for heating by the exhaust gas of the engine the heavyfuel before its transformation into fuel air-mixture, a small explosion chamber forming an ignition amplifier and fed through an admission valve with a gaseous volatile mixture, a spark plug for said chamber, a conduit serving to direct into the engine cylinder the ignited jet, a communication between the main induction valve of the engine and simultaneously with a source of supply of the heavy fuel-air-mixture and with a source of light fuel-air-mixture, and means for controlling the proportion of light and heavy fuel-airmixtures induced through the main valve, said means being such that the engine induces either the light fuel-air-inixture alone or the heavy fuelair-mixture alone or the two mixtures simultaneously in any and instantaneously variable pro- 5 portions.

2. System for feeding an internal combustion engine with light fuel, such as petrol, and heavy fuel, such as gas oil, comprising means for heating by the exhaust gas of the engine the heavy 10 fuel before its transformation into fuel-air-mixture, a small explosion chamber forming an ignition amplifier and fed through an admission valve with a gaseous volatile mixture, a spark plug for said chamber, a conduit serving to direct into15 the engine cylinder the ignited jet, two separate carburettors for feeding the engine with light fuelair-mixture and heavy fuel-air-mixture, the two carburettor-s being connected to the cylinder inlet manifold by a three-way conduit provided in its 20 outlet branch with a throttle for controlling the induction, the respective throttles of the two carburettors being coupled so that the one is closed when the other is open and being actuable simultaneously so as to permit induction instantane- 25 ously throughone or the other carburettor, or through both carhurettors in any and instantaneously variable proportions.

3. A system according to claim 1 wherein means for actuating the admission valve of the 30 amplifier comprises an adjustable system in op-= erative combination with a removable element interposable in the drive to'the ignition interrupter of an engine.

i. A system according to claim 1 wherein the 35 admission valve actuating means comprise elements adjustable to permit the timing and degree of opening of the valve to be varied.

5.-An internal combustion engine comprising a system according to claim 1 wherein a plurality 4g of ignition amplifiers are attached in pairs by means of single bolts each anchored in a stirrup secured by the holding-down bolts of thecylinder block. the said bolt pressing a. cross-piece upon the two ignition amplifiers. 45

RAQUL PIERRE MABIUS sooner. 

